﻿namespace Lucene.Net.Facet.Taxonomy
{


	/*
	 * Licensed to the Apache Software Foundation (ASF) under one or more
	 * contributor license agreements.  See the NOTICE file distributed with
	 * this work for additional information regarding copyright ownership.
	 * The ASF licenses this file to You under the Apache License, Version 2.0
	 * (the "License"); you may not use this file except in compliance with
	 * the License.  You may obtain a copy of the License at
	 *
	 *     http://www.apache.org/licenses/LICENSE-2.0
	 *
	 * Unless required by applicable law or agreed to in writing, software
	 * distributed under the License is distributed on an "AS IS" BASIS,
	 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	 * See the License for the specific language governing permissions and
	 * limitations under the License.
	 */

	/// <summary>
	/// Returns 3 arrays for traversing the taxonomy:
	/// <ul>
	/// <li>{@code parents}: {@code parents[i]} denotes the parent of category
	/// ordinal {@code i}.</li>
	/// <li>{@code children}: {@code children[i]} denotes a child of category ordinal
	/// {@code i}.</li>
	/// <li>{@code siblings}: {@code siblings[i]} denotes the sibling of category
	/// ordinal {@code i}.</li>
	/// </ul>
	/// 
	/// To traverse the taxonomy tree, you typically start with {@code children[0]}
	/// (ordinal 0 is reserved for ROOT), and then depends if you want to do DFS or
	/// BFS, you call {@code children[children[0]]} or {@code siblings[children[0]]}
	/// and so forth, respectively.
	/// 
	/// <para>
	/// <b>NOTE:</b> you are not expected to modify the values of the arrays, since
	/// the arrays are shared with other threads.
	/// 
	/// @lucene.experimental
	/// </para>
	/// </summary>
	public abstract class ParallelTaxonomyArrays
	{

	  /// <summary>
	  /// Sole constructor. </summary>
	  public ParallelTaxonomyArrays()
	  {
	  }

	  /// <summary>
	  /// Returns the parents array, where {@code parents[i]} denotes the parent of
	  /// category ordinal {@code i}.
	  /// </summary>
	  public abstract int[] Parents();

	  /// <summary>
	  /// Returns the children array, where {@code children[i]} denotes a child of
	  /// category ordinal {@code i}.
	  /// </summary>
	  public abstract int[] Children();

	  /// <summary>
	  /// Returns the siblings array, where {@code siblings[i]} denotes the sibling
	  /// of category ordinal {@code i}.
	  /// </summary>
	  public abstract int[] Siblings();

	}

}